1. Field of the Invention
The invention relates to ball valves; and, more particularly, to an end entry ball valve having an improved seal on the ball stem sealing off fluids in the interior of the valve from the exterior thereof.
2. Description of the Prior Art
Ball valves are well known in the art. Such valves generally include a main valve body having a throughbore with an apertured ball mounted in the throughbore. The ball is rotated by a valve stem passing out of the valve body so that the aperture in the ball can be selectively aligned with the throughbore through the valve body. Such end entry prior art ball valves are assembled by inserting the valve stem from inside the body. An O-ring is mounted in a groove on the stem to seal off fluid inside the valve from the exterior. The valve stem is inserted through a hole in the valve body. This hole requires a chamfer or counterbore to compress and guide the O-ring up into the stem hole. This counterbore, formed on the interior wall of the valve body surrounding the stem hole, is expensive to machine and requires a considerable amount of time to do so.
There is thus a need for a means for compressing and guiding the O-ring on a valve stem up into a seat on the valve stem hole without need for expensive and time consuming machining.